Percentages are immensely useful for determining quantities and proportions. They are also useful in making educated predictions of outcomes; for example, there is a 50 percent chance of flipping a "heads" on a coin toss. Starting kids off early in percentages gives them a better understanding of probabilities, fractions and quantities. When instructing kids, there are a few basic points that must be addressed.
Draw a series of 10 squares on the chalk board, and fill in 3 of them.
Ask the kids what fraction of the squares is filled. If they are unsure, give them the answer and explain.
Ask the kids for the decimal version of the fraction. If they need help, tell them it is simply division: 3 divided by 10 equals 0.30.
Have the kids calculate the percentage of 3 divided by 10. Explain that a "percent" simply means "per one hundred," and to calculate a percent, you simply multiply by 100. In the example, 0.30 blocks is multiplied by 100 to produce 30 percent. Further tell them that the easiest way to convert a number to a percent is to move the decimal point two places to the right.
Lay out several coins and a dollar bill. Explain that there are 100 cents to a dollar, and the coins can represent a fraction of a dollar. As an example, 25 cents is 25/100 of a dollar. Since the fraction of this is 0.25, then a quarter represents 25 percent of a dollar. Likewise, a penny is 1 percent, a nickel is 5 percent and a dime is 10 percent.
Lay out one of each coin (a quarter, a dime, a nickle and a penny) and ask the kids to add the coins and calculate the sum's percentage of a dollar. If their answer isn't 41 percent, help them figure out the correct percentage.